Battery Challenge Experiment




Description



This is an experiment to test whether certain variables may affect the efficiency of a battery. Our 'battery' consists of two thin pieces of aluminum and copper in a beaker of salt water. According to our previous experiment, we can connect the two pieces of metal in order to create electricity. Our current experiment is to test whether altering the amount of salt water will change the efficiency of the battery.

Hypothesis



By adding more salt water in the beaker, we can expect the efficiency of the battery to increase because there will be more salt water to conduct the electricity.

Dependent Variable: Amount of salt water we have in the beaker.
Independent Variables: The size of the metals, the water to salt ratio in the concentration, the temperature of the liquid.

Materials Used



Aluminum: 16.48 grams
Copper: 51.03 grams
Voltmeter and Wires
1000mL Beaker
100mL Graduated Cylinder
Salt Water Concentration

Procedure



1) Get one piece of Copper and Aluminum, both about 10x4 cm.
2) Use the 100mL Graduated Cylinder to measure out 100mL of water.
3) Use the 25mL Graduated Cylinder to measure out 25mL of salt.
4) Mix them together using the 1000mL beaker.
5) Put the aluminum and copper pieces into the beaker so that they don't touch.
6) Connect each metal piece to a wire, and connect the wires to the voltmeter.
7) Record the observations.

We repeated this procedure five times, each time increasing the amount of water by 100mL and the amount of salt by 25mL.

Ratios



Water (milliliters)
Salt (milliliters)
100mL
25mL
200mL
50mL
300mL
75mL
400mL
100mL
500mL
125mL
Approximate Weight of 25mL of Salt: 34.7 +/- 0.02 grams.

Observations




Amount of Solution
Voltage +/- 0.01 mV
Amps +/- 0.2 mA
100mL
0.490 mV
3 --> decreasing
200mL
0.530 mV
5.2 --> decreasing
300mL
0.545 mV
18 --> decreasing
400mL
0.548 mV
19 --> decreasing
500mL
0.520 mV
20 --> decreasing
According to our observations, the voltage continued to steadily increase until we reached 500mL of water.


Data



aac1.JPGaac.JPG

These two graphs show that although the voltage increased as we added water, the change wasn't substantial.

aad.JPG